Golf Club Head or Other Ball Striking Device Having Impact-Influencing Body Features

ABSTRACT

A ball striking device, such as a golf club head, has a face with a striking surface configured for striking a ball; an elongated channel extending across a portion of the sole, wherein the sole the sole has an elongated channel recessed from adjacent surfaces. The elongated channel is made of a plurality of materials such that the materials making up the elongated channel have a lower modulus of elasticity than the modulus of elasticity of the material remainder of the sole. The lower modulus materials help to control the flexibility of the elongated channel, which can improve the efficiency of the impact with a golf ball.

TECHNICAL FIELD

The invention relates generally to golf club heads and other ball striking devices that include impact influencing body features. Certain aspects of this invention relate to golf club heads and other ball striking devices that have a face member containing a portion of the ball striking face and a portion of the crown along with an elongated channel positioned on the sole oriented in the heel-to-toe direction made of more flexible materials than the remainder of the sole.

BACKGROUND

Golf clubs and many other ball striking devices may have various face and body features, as well as other characteristics that can influence the use and performance of the device. For example, users may wish to have improved impact properties, such as increased coefficient of restitution (COR) in the face, increased size of the area of greatest response or COR (also known as the “hot zone”) of the face, and/or improved efficiency of the golf ball on impact. The COR is defined as a ratio of the relative speed of the ball after impact divided by the relative speed of the ball before the impact. Since a significant portion of the energy loss during an impact of a golf club head with a golf ball is a result of energy loss as the golf ball deforms, reducing deformation of the golf ball during impact may increase energy transfer and velocity of the golf ball after impact, which benefits the golfer in the form of greater distance. The present devices and methods are provided to address at least some of these problems and other problems, and to provide advantages and aspects not provided by prior ball striking devices. A full discussion of the features and advantages of the present invention is deferred to the following detailed description, which proceeds with reference to the accompanying drawings.

BRIEF SUMMARY

The following presents a general summary of aspects of the invention in order to provide a basic understanding of the invention. This summary is not an extensive overview of the invention. It is not intended to identify key or critical elements of the invention or to delineate the scope of the invention. The following summary merely presents some concepts of the invention in a general form as a prelude to the more detailed description provided below.

Aspects of the disclosure relate to a ball striking device, such as a golf club head, having a club head body member made of a first material comprising a heel, a toe, a portion of a crown, a portion of a sole, a face member made of a second material comprising a central portion of the striking surface configured for striking a ball and a surface that comprises a portion of the crown, a sole made of a plurality of materials, an elongated channel extending across a portion of the sole in a heel-to-toe direction, wherein the elongated channel is recessed from adjacent surfaces of the sole and has a plurality of side walls and a depth of recession from the adjacent surfaces of the sole. The elongated channel and a portion of the adjacent surfaces and are made of at least a third material and the remainder of the elongated channel is made of a fourth material where the third material and the fourth material have a lower modulus of elasticity than the first material on the remainder of the sole.

Other aspects of the disclosure relate to a golf club or other ball striking device including a head or other ball striking device as described above and a shaft connected to the head/device and configured for gripping by a user. Aspects of the disclosure relate to a set of golf clubs including at least one golf club as described above. Yet additional aspects of the disclosure relate to a method for manufacturing a ball striking device as described above, including assembling a head as described above and/or connecting a handle or shaft to the head.

Other features and advantages of the invention will be apparent from the following description taken in conjunction with the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

To allow for a more full understanding of the present invention, it will now be described by way of example, with reference to the accompanying drawings in which:

FIG. 1 is a front view of one embodiment of a golf club with a golf club head according to aspects of the disclosure, in the form of a golf driver;

FIG. 2 is a bottom right rear perspective view of the golf club head of FIG. 1;

FIG. 3 is a front view of the club head of FIG. 1, showing a ground plane origin point;

FIG. 4 is a front view of the club head of FIG. 1, showing a hosel origin point;

FIG. 5 is a top view of the club head of FIG. 1;

FIG. 6 is a front view of the club head of FIG. 1;

FIG. 7 is a side view of the club head of FIG. 1;

FIG. 8 is a cross-section view taken along line 8-8 of FIG. 6, with a magnified portion also shown;

FIG. 8A is a magnified view of a portion of FIG. 8;

FIG. 9 is a bottom view of the club head of FIG. 1;

FIG. 10 is a magnified view of a portion of an alternate embodiment of the club head of FIG. 8;

FIG. 11 is a magnified view of a portion of an alternate embodiment of the club head of FIG. 8;

FIG. 12 is a magnified view of a portion of an alternate embodiment of the club head of FIG. 8;

DETAILED DESCRIPTION

In the following description of various example structures according to the invention, reference is made to the accompanying drawings, which form a part hereof, and in which are shown by way of illustration various example devices, systems, and environments in which aspects of the invention may be practiced. It is to be understood that other specific arrangements of parts, example devices, systems, and environments may be utilized and structural and functional modifications may be made without departing from the scope of the present invention. Also, while the terms “top,” “bottom,” “front,” “back,” “side,” “rear,” and the like may be used in this specification to describe various example features and elements of the invention, these terms are used herein as a matter of convenience, e.g., based on the example orientations shown in the figures or the orientation during typical use. Additionally, the term “plurality,” as used herein, indicates any number greater than one, either disjunctively or conjunctively, as necessary, up to an infinite number. Nothing in this specification should be construed as requiring a specific three dimensional orientation of structures in order to fall within the scope of this invention. Also, the reader is advised that the attached drawings are not necessarily drawn to scale.

The following terms are used in this specification, and unless otherwise noted or clear from the context, these terms have the meanings provided below.

“Ball striking device” means any device constructed and designed to strike a ball or other similar objects (such as a hockey puck). In addition to generically encompassing “ball striking heads,” which are described in more detail below, examples of “ball striking devices” include, but are not limited to: golf clubs, putters, croquet mallets, polo mallets, baseball or softball bats, cricket bats, tennis rackets, badminton rackets, field hockey sticks, ice hockey sticks, and the like.

“Ball striking head” (or “head”) means the portion of a “ball striking device” that includes and is located immediately adjacent (optionally surrounding) the portion of the ball striking device designed to contact the ball (or other object) in use. In some examples, such as many golf clubs and putters, the ball striking head may be a separate and independent entity from any shaft member, and it may be attached to the shaft in some manner.

The terms “shaft” or “handle” include the portion of a ball striking device (if any) that the user holds during a swing of a ball striking device.

“Integral joining technique” means a technique for joining two pieces so that the two pieces effectively become a single, integral piece, including, but not limited to, irreversible joining techniques, such as adhesively joining, cementing, welding, brazing, soldering, or the like, where separation of the joined pieces cannot be accomplished without structural damage thereto. Pieces joined with such a technique are described as “integrally joined.”

“Generally parallel” means that a first line, segment, plane, edge, surface, etc. is approximately (in this instance, within 5%) equidistant from with another line, plane, edge, surface, etc., over at least 50% of the length of the first line, segment, plane, edge, surface, etc.

“Substantially constant” when referring to a dimension means that a value is approximately the same and varies no more than +/−5%.

In general, aspects of this invention relate to ball striking devices, such as golf club heads, golf clubs, and the like. Such ball striking devices, according to at least some examples of the invention, may include a ball striking head with a ball striking surface. In the case of a golf club, the ball striking surface is a substantially flat surface on one face of the ball striking head. Some more specific aspects of this invention relate to wood-type golf clubs and golf club heads, including drivers, fairway woods, hybrid clubs, and the like, although aspects of this invention also may be practiced in connection with iron-type clubs, putters, and other club types as well.

According to various aspects and embodiments, the ball striking device may be formed of one or more of a variety of materials, such as metals (including metal alloys), ceramics, polymers, composites (including fiber-reinforced composites), and wood, and may be formed in one of a variety of configurations, without departing from the scope of the invention. In one illustrative embodiment, some or all components of the head, including the face and at least a portion of the body of the head, are made of metal (the term “metal,” as used herein, includes within its scope metal alloys, metal matrix composites, and other metallic materials). It is understood that the head may contain components made of several different materials, including carbon-fiber composites, polymer materials, and other components. Additionally, the components may be formed by various forming methods. For example, metal components, such as components made from titanium, aluminum, titanium alloys, aluminum alloys, steels (including stainless steels), and the like, may be formed by forging, molding, casting, stamping, machining, and/or other known techniques. In another example, composite components, such as carbon fiber-polymer composites, can be manufactured by a variety of composite processing techniques, such as prepreg processing, powder-based techniques, mold infiltration, and/or other known techniques. In a further example, polymer components, such as high strength polymers, can be manufactured by polymer processing techniques, such as various molding and casting techniques and/or other known techniques.

The various figures in this application illustrate examples of ball striking devices according to this invention. When the same reference number appears in more than one drawing, that reference number is used consistently in this specification and the drawings refer to the same or similar parts throughout.

At least some examples of ball striking devices according to this invention relate to golf club head structures, including heads for wood-type golf clubs, such as drivers, fairway woods and hybrid clubs, as well as other types of wood-type clubs. Such devices may include a one-piece construction or a multiple-piece construction. Example structures of ball striking devices according to this invention will be described in detail below in conjunction with FIGS. 1-9 which illustrate one illustrative embodiment of a ball striking device 100 in the form of a wood-type golf club (e.g. a driver). FIGS. 10-12 illustrate alternate embodiments of a driver version of golf club head 102. As mentioned previously, aspects of this disclosure may alternately be used in connection with long iron clubs (e.g., driving irons, zero irons through five irons, and hybrid type golf clubs), short iron clubs (e.g., six irons through pitching wedges, as well as sand wedges, lob wedges, gap wedges, and/or other wedges), and putters.

The golf club 100 shown in FIG. 1 includes a golf club head or a ball striking head 102 configured to strike a ball in use and a shaft 104 connected to the ball striking head 102 and extending therefrom. FIGS. 1-9 illustrate one embodiment of a ball striking head in the form of a golf club head 102 that has a face member 112 connected to a body 108, with a hosel 110 extending therefrom and a shaft 104 connected to the hosel 110. For reference, the head 102 generally has a top or crown 116, a bottom or sole 118, a heel 120 proximate the hosel 110, a toe 122 distal from the hosel 110, a front 124, and a back or rear 126, as shown in FIGS. 1-9. The shape and design of the head 102 may be partially dictated by the intended use of the golf club 100. For example, it is understood that the sole 118 is configured to face the playing surface in use. With clubs that are configured to be capable of hitting a ball resting directly on the playing surface, such as a fairway wood, hybrid, iron, etc., the sole 118 may contact the playing surface in use, and features of the club may be designed accordingly. In the club 100 shown in FIGS. 1-12, the head 102 has an enclosed volume, measured per “USGA PROCEDURE FOR MEASURING THE CLUB HEAD SIZE OF WOOD CLUBS”, TPX-3003, REVISION 1.0.0 dated Nov. 21, 2003, as the club 100 is a wood-type club designed for use as a driver, intended to hit the ball long distances. In this procedure, the volume of the club head is determined using the displaced water weight method. According to the procedure, any large concavities must be filled with clay or dough and covered with tape so as to produce a smooth contour prior to measuring volume. Club head volume may additionally or alternately be calculated from three-dimensional computer aided design (CAD) modeling of the golf club head. In other applications, such as for a different type of golf club, the head 102 may be designed to have different dimensions and configurations. For example, when configured as a driver, the club head 102 may have a volume of at least 400 cc, and in some structures, at least 450 cc, or even at least 470 cc. The head 102 illustrated in the form of a driver in FIGS. 1-12 has a volume of approximately 460 cc. If instead configured as a fairway wood, the head may have a volume of 120 cc to 250 cc, and if configured as a hybrid club, the head may have a volume of 85 cc to 170 cc. Other appropriate sizes for other club heads may be readily determined by those skilled in the art. The loft angle of the club head 102 also may vary, e.g., depending on the distance the club 100 is designed to hit the ball. For example, a driver golf club head may have a loft angle range of 7 degrees to 16 degrees, a fairway wood golf club head may have a loft angle range of 12 to 25 degrees, and a hybrid golf club head may have a loft angle range of 16 to 28 degrees.

The body 108 of the head 102 can have various different shapes, including a rounded shape, as in the head 102 shown in FIGS. 1-12, a generally square or rectangular shape, or any other of a variety of other shapes. It is understood that such shapes may be configured to distribute weight in any desired, manner, e.g., away from the ball striking surface 114 and/or the geometric/volumetric center of the head 102, to create a lower center of gravity and/or a higher moment of inertia.

In the illustrative embodiment illustrated in FIGS. 1-9, the head 102 has a hollow structure defining an inner cavity 103 (e.g., defined by the face member 112 and the club head body 108) with a plurality of inner surfaces defined therein. In one embodiment, the inner cavity 103 may be filled with air. However, in other embodiments, the inner cavity 103 could be filled or partially filled with another material, such as foam or hot melt glue. In still further embodiments, the solid materials of the head may occupy a greater proportion of the volume, and the head may have a smaller cavity or no inner cavity 103 at all. It is understood that the inner cavity 103 may not be completely enclosed in some embodiments.

The face member 112 is located at the front 124 of the head 102 and comprises a portion of the ball striking surface (or striking surface) 111 located thereon, an inner surface 107 opposite the ball striking surface 111, and a flange 129 as illustrated in FIG. 3. The edges 128 of the ball striking surface may be defined as the boundaries of an area of the ball striking surface 114 that is specifically designed to contact the ball in use, and may be recognized as the boundaries of an area of the ball striking surface 114 that is intentionally shaped and configured to be suited for ball contact. The ball striking surface 114 has an outer periphery formed of a plurality of outer or peripheral edge 128. The ball striking surface 114 comprises a portion of the ball striking surface 111 of face member 112 along with the other portions of the ball striking surface at the toe 117 and at the heel 115 within the peripheral edge 128. The face member's ball striking surface 111 may make up at least 70 percent of the surface area of the ball striking surface 114, or at least 80 percent of the surface area of the ball striking surface 114, or 100 percent of the surface area of the ball striking surface 114.

The face member 112 also has a flange 129 that comprises a portion of the crown surface 116. The addition of the flange onto the face member moves the weld or connecting feature of the face to the body away from the striking face thereby helping to improve the strength in that region, which can improve the impact efficiency and durability of the striking face. For example, the face member 112 may be made of a material, which may have a modulus of elasticity lower than the material used for the club head body or the face member material may be the same material as the club head body. For example, the face member material may be a titanium alloy like Ti-6Al-4V alloy or similar titanium alloy, a beta-titanium alloy, a steel alloy, Gum Metal™, an amorphous metal, or even a polymer or non-metallic material. As an alternate embodiment, the face member 112 may comprise only the ball striking surface portion 111 as a face-pull club head construction.

In general, the ball striking heads 102 according to the present invention include features on the body 108 that influence the impact of a ball on the face member 112, such as one or more elongated channels 140 positioned on the body 108 of the head 102 that allow at least a portion of the body 108 to flex, produce a reactive force, and/or change the behavior or motion of the face member 112, during impact of a ball on the face member 112. In the golf club 100 shown in FIGS. 1-9, the head 102 includes a single elongated channel 140 located on the sole 118 of the head 102. The sole 118 comprises a plurality of members where at least a first member 136 may be made of a first material, a second member 138 may be made of a third material with a lower modulus of elasticity than the first material, and a third member 160 may be made of a fourth material with a lower modulus of elasticity than the third material. The elongated channel 140 may be formed by a plurality of materials within the second member 138 and third member 160. The elongated channel 140 may be comprised entirely of the second and third members or the third member may comprise only a portion of the elongated channel. For example, the second member 138 may form a portion of the adjacent surfaces to the elongated channel along with a portion of the side walls and the third member 160 may form only a portion of the side walls and trough. Alternatively, the second member 138 may form a portion of the adjacent surfaces, side walls, and the trough in certain areas where the third member 160 may only be located in a center portion, on a heel side, on a toe side, or on the heel and toe sides. The second member 138 may be integrally joined to the first member 136 on at least four sides while the third member 160 is integrally joined to the second member 138 on at least four sides. Alternatively, the second member 138 may have a plurality of portions attached to a first member 136 on at least three sides and attached to the third member 160 on at least one side, where the third member 160 is attached to the second member 138 at its forward edge 162 and its rear edge 164 and to the first member on a heel edge 166 and a toe edge 168.

The first member 136 may be made of a titanium alloy similar to Ti-8Al-1Mo-1V or Ti-6Al-4V alloy, the second member 138 may be a material with a lower modulus of elasticity than the first material such as a beta-titanium alloy, Gum Metal™, vitreous alloys, metallic glasses or other amorphous metallic materials, non-metallic material, composite materials (carbon fiber and others), or other suitable material, and the third member 160 may be a third material with a lower modulus of elasticity than the second material such as a beta-titanium alloy, Gum Metal™, vitreous alloys, metallic glasses or other amorphous metallic materials, non-metallic material, composite materials (carbon fiber and others), or other suitable material. Having a channel with a plurality of materials that have a lower modulus of elasticity can create a more flexible channel which can allow for more flexing during the impact of a ball with the face member 112 while not exceeding the yield stress causing permanent deformation, while also allowing different portions of the channel to flex at different rates. As described below, this channel 140 permits compression and flexing of the body 108 during impact on the face member 112, which can influence the impact properties of the club head. This illustrative embodiment and other embodiments are described in greater detail below.

The modulus of elasticity is a measurement of a material's resistance to a force and not be permanently deformed. The higher the modulus of elasticity, the stiffer the material. By having a modulus of elasticity lower than that of the first material, the second member creates an area that may deform greater than the surrounding area during the impact with a golf ball. This deformation within the body, as long as it does not cause permanent deformation of the material, may improve the efficiency of the collision or COR by keeping a golf ball from losing as much energy during an impact with a golf club.

The club head body may be made of a titanium alloy. Titanium alloys may have a variety of modulus of elasticity properties, but typically range between 100 GPa and 140 GPa. For example, the modulus of elasticity of common titanium alpha-beta alloys such as Ti-6Al-4V alloy is approximately 114 GPa, while Ti-8Al-1Mo-1V which is an alpha/near alpha alloy has a modulus of approximately 121 GPa. While a typical beta titanium alloy such as Ti-15V-3Cr-3Sn-3Al has a modulus of approximately 100 GPa. For some titanium alloys, the elastic modulus may be affected by cold working a titanium alloy and aligning the grain structure in a specific direction. For example, the titanium alloy SP700 from JFE steel may have a modulus of elasticity ranging from approximately 109 GPa to 137 GPa depending upon the direction the grain is oriented after cold working.

However, Gum Metal™ is a unique titanium alloy that has a combination of a relatively low modulus of elasticity with a yield strength comparable or higher than titanium alloys. Gum Metal™ may have a modulus of elasticity of approximately 80 GPa or in a range of 85 GPa to 95 GPa, but the modulus of elasticity may be modified by a work hardening process, like cold working, to approximately 45 GPa, or in a range between 30 GPa and 60 GPa. However, Gum Metal™ may have a density of approximately 5.6 grams per cubic centimeter, which is higher than that of a titanium alloy, which may be within a range of 4.5 to 4.8 grams per cubic centimeter. This lower modulus of elasticity combined with its high yield strength may make it an ideal material to provide an elastically deformable region in the golf club body, while the higher density may restrict the use of Gum Metal™ to targeted regions.

The various embodiments of golf clubs 100 and/or golf club heads 102 described herein may include components that have sizes, shapes, locations, orientations, etc., that are described with reference to one or more properties and/or reference points. Several of such properties and reference points are described in the following paragraphs, with reference to FIGS. 3-8.

As illustrated in FIG. 3, a lie angle 2 is defined as the angle formed between the hosel axis 4 or a shaft axis 5 and a horizontal plane contacting the sole 118, i.e., the ground plane 6. It is noted that the hosel axis 4 and the shaft axis 5 are central axes along which the hosel 110 and shaft 104 extend.

One or more origin points 8 (e.g., 8A, 8B) may be defined in relation to certain elements of the golf club 100 or golf club head 102. Various other points, such as a center of gravity, a sole contact, and a face center, may be described and/or measured in relation to one or more of such origin points 8. FIGS. 3 and 4 illustrate two different examples such origin points 8, including their locations and definitions. A first origin point location, referred to as a ground plane origin point 8A is generally located at the ground plane 6. The ground plane origin point 8A is defined as the point at which the ground plane 6 and the hosel axis 4 intersect. A second origin point location, referred to as a hosel origin point 8B, is generally located on the hosel 110. The hosel origin point 8B is defined on the hosel axis 4 and coincident with the uppermost edge of the hosel 110. Either location for the origin point 8, as well as other origin points 8, may be utilized for reference without departing from this invention. It is understood that references to the ground plane origin point 8A and hosel origin point 8B are used herein consistent with the definitions in this paragraph, unless explicitly noted otherwise. Throughout the remainder of this application, the ground plane origin point 8A will be utilized for all reference locations, tolerances, calculations, etc., unless explicitly noted otherwise.

As illustrated in FIG. 3, a coordinate system may be defined with an origin located at the ground plane origin point 8A, referred to herein as a ground plane coordinate system. In other words, this coordinate system has an X-axis 14, a Y-axis 16, and a Z-axis 18 that all pass through the ground plane origin point 8A. The X-axis in this system is parallel to the ground plane and generally parallel to the striking surface 114 of the golf club head 102. The Y-axis 16 in this system is perpendicular to the X-axis 14 and parallel to the ground plane 6, and extends towards the rear 126 of the golf club head 102, i.e., perpendicular to the plane of the drawing sheet in FIG. 3. The Z-axis 18 in this system is perpendicular to the ground plane 6, and may be considered to extend vertically. Throughout the remainder of this application, the ground plane coordinate system will be utilized for all reference locations, tolerances, calculations, etc., unless explicitly noted otherwise.

FIGS. 3 and 5 illustrate an example of a center of gravity location 26 as a specified parameter of the golf club head 102, using the ground plane coordinate system. The center of gravity of the golf club head 102 may be determined using various methods and procedures known and used in the art. The golf club head 102 center of gravity location 26 is provided with reference to its position from the ground plane origin point 8A. As illustrated in FIGS. 3 and 5, the center of gravity location 26 is defined by a distance CGX 28 from the ground plane origin point 8A along the X-axis 14, a distance CGY 30 from the ground plane origin point 8A along the Y-axis 16, and a distance CGZ 32 from the ground plane origin point 8A along the Z-axis 18.

Additionally, as illustrated in FIG. 4, another coordinate system may be defined with an origin located at the hosel origin point 8B, referred to herein as a hosel axis coordinate system. In other words, this coordinate system has an X′ axis 22, a Y′ axis 20, and a Z′ axis 24 that all pass through the hosel origin point 8B. The Z′ axis 24 in this coordinate system extends along the direction of the shaft axis 5 (and/or the hosel axis 4). The X′ axis 22 in this system extends parallel with the vertical plane and normal to the Z′ axis 24. The Y′ axis 20 in this system extends perpendicular to the X′ axis 22 and the Z′ axis 24 and extends toward the rear 126 of the golf club head 102, i.e., the same direction as the Y-axis 16 of the ground plane coordinate system.

FIG. 4 illustrates an example of a center of gravity location 26 as a specified parameter of the golf club head 102, using the hosel axis coordinate system. The center of gravity of the golf club head 102 may be determined using various methods and procedures known and used in the art. The golf club head 102 center of gravity location 26 is provided with reference to its position from the hosel origin point 8B. As illustrated in FIG. 4, the center of gravity location 26 is defined by a distance ΔX 34 from the hosel origin point 8B along the X′ axis 22, a distance ΔY (not shown) from the hosel origin point 8B along the Y′ axis 20, and a distance ΔZ 38 from the hosel origin point 8B along the Z′ axis 24.

FIGS. 5 and 6 illustrate the face center (FC) location 40 on a golf club head 102. The face center location 40 illustrated in FIGS. 4 and 5 is determined using United States Golf Association (USGA) standard measuring procedures from the “Procedure for Measuring the Flexibility of a Golf Clubhead”, USGA TPX-3004, Revision 2.0, Mar. 25, 2005. Using this USGA procedure, a template is used to locate the FC location 40 from both a heel 120 to toe 122 location and a crown 116 to sole 118 location. For measuring the FC location 40 from the heel-to-toe location, the template should be placed on the striking surface 114 until the measurements at the edges of the striking surface 114 on both the heel 120 and toe 122 are equal. This marks the FC location 40 from a heel-to-toe direction. To find the face center from a crown to sole dimension, the template is placed on the striking surface 114 and the FC location 40 from crown to sole is the location where the measurements from the crown 116 to sole 118 are equal. The FC location 40 is the point on the striking surface 114 where the crown-to-sole measurements on the template are equidistant, and the heel-to-toe measurements are equidistant.

As illustrated in FIGS. 5 and 6, the FC location 40 can be defined from the ground plane origin coordinate system, such that a distance CFX 42 is defined from the ground plane origin point 8A along the X-axis 14, a distance CFY 44 is defined from the ground plane origin point 8A along the Y-axis 16, and a distance CFZ 46 is defined from the ground plane origin point 8A along the Z-axis 18. It is understood that the FC location 40 may similarly be defined using the hosel origin system, if desired. The face progression (FP) 31 may be determined as the distance from the center axis of the hosel or origin point 8A to the forward most edge of the head 102 along the Y-Axis 16.

FIG. 7 illustrates an example of a loft angle 48 of the golf club head 102. The loft angle 48 can be defined as the angle between plane 51 that is tangential to the club head at the FC location 40 and a plane normal or perpendicular to the ground plane 6. Alternately, the loft angle 48 can be defined as the angle between an axis 50 normal or perpendicular to the striking surface 114 at the FC location 40, called a face center axis 50, and the ground plane 6. It is understood that each of these definitions of the loft angle 48 may yield the substantially the same loft angle measurement. Additionally, a sole-face intersection point 68 may be defined as the point where plane 51 intersects the ground plane 6 at a plane parallel to the Z-axis through the FC location 40.

FIG. 5 illustrates an example of a face angle 52 of a golf club head 102. As illustrated in FIG. 5, the face angle 52 is defined as the angle between the face center axis 50 and a plane 54 perpendicular to the X-axis 14 and the ground plane 6.

FIG. 3 illustrates a golf club head 102 oriented in a reference position. In the reference position, the hosel axis 4 or shaft axis 5 lies in a vertical plane, as shown in FIG. 7. As illustrated in FIG. 3, the hosel axis 4 may be oriented at the lie angle 2. The lie angle 2 selected for the reference position may be the golf club 100 manufacturer's specified lie angle. If a specified lie angle is not available from the manufacturer, a lie angle of 60 degrees can be used. Furthermore, for the reference position, the striking surface 114 may, in some circumstances, be oriented at a face angle 54 of 0 degrees. The measurement setup for establishing the reference position can be found determined using the “Procedure for Measuring the Club Head Size of Wood Clubs”, TPX-3003, and Revision 1.0.0, dated Nov. 21, 2003.

As golf clubs have evolved in recent years, many have incorporated head/shaft interconnection structures connecting the shaft 104 and club head 102. These interconnection structures are used to allow a golfer to easily change shafts for different flex, weight, length or other desired properties. Many of these interconnection structures have features whereby the shaft 104 is connected to the interconnection structure at a different angle than the hosel axis 4 of the golf club head, including the interconnection structures discussed elsewhere herein. This feature allows these interconnection structures to be rotated in various configurations to potentially adjust some of the relationships between the club head 102 and the shaft 104 either individually or in combination, such as the lie angle, the loft angle, or the face angle. As such, if a golf club 100 includes an interconnection structure, it shall be attached to the golf club head when addressing any measurements on the golf club head 102. For example, when positioning the golf club head 102 in the reference position, the interconnection structures should be attached to the structure. Since this structure can influence the lie angle, face angle, and loft angle of the golf club head, the interconnection member shall be set to its most neutral position. Additionally, these interconnection members have a weight that can affect the golf club heads mass properties, e.g. center of gravity (CG) and moment of inertia (MOI) properties. Thus, any mass property measurements on the golf club head should be measured with the interconnection member attached to the golf club head.

The moment of inertia is a property of the club head 102, the importance of which is known to those skilled in the art. There are three moment of inertia properties referenced herein. The moment of inertia with respect to an axis parallel to the X-axis 14 of the ground plane coordinate system, extending through the center of gravity 26 of the club head 102, is referenced as the MOI x-x, as illustrated in FIG. 7. The moment of inertia with respect to an axis parallel to the Z-axis 18 of the ground plane coordinate system, extending through the center of gravity 26 of the club head 102, is referenced as the MOI z-z, as illustrated in FIG. 5. The moment of inertia with respect to the Z′ axis 24 of the hosel axis coordinate system is referenced as the MOI h-h, as illustrated in FIG. 4. The MOI h-h can be utilized in determining how the club head 102 may resist the golfer's ability to close the clubface during the swing.

The ball striking face height (FH) 56 is a measurement taken along a plane normal to the ground plane and defined by the dimension CFX 42 through the face center 40, of the distance between the ground plane 6 and a point represented by a midpoint 62 of a radius between the crown 116 and the face member 112. An example of the measurement of the face height 56 of a head 102 is illustrated in FIG. 8. It is understood that the club heads 102 described herein may be produced with multiple different loft angles, and that different loft angles may have some effect on face height 56.

The head length 58 and head breadth 60 measurements can be determined by using the USGA “Procedure for Measuring the Club Head Size of Wood Clubs,” USGA-TPX 3003, Revision 1.0.0, dated Nov. 21, 2003. Examples of the measurement of the head length 58 and head breadth 60 of a head 102 are illustrated in FIGS. 4 and 5.

In the golf club 100 shown in FIGS. 1-12, the head 102 has dimensional characteristics that define its geometry and also has specific mass properties that can define the performance of the golf club as it relates to the ball flight that it imparts onto a golf ball during the golf swing or the impact event itself. This illustrative embodiment and other embodiments are described in greater detail below.

The head 102 as shown in FIGS. 1-12 illustrates a driver golf club head. As known to one skilled in the art, the mass properties of a club head may have a significant effect on the impact efficiency. For example, the head 102 may have a head weight of approximately 198 to 210 grams, or 190 to 220 grams or even 188 to 240 grams. The head 102 may have an MOI x-x of approximately 2500 g*cm² to 2700 g*cm², or approximately 2400 g*cm² to 2800 g*cm², or approximately 2000 g*cm² to 3000 g*cm². Additionally, the head 102 may have an MOI z-z of approximately 4400 g*cm² to 4800 g*cm², or approximately 4200 g*cm² to 5000 g*cm², or approximately 4000 g*cm² to 5400 g*cm². The head 102 when configured as a driver generally has a head length ranging of approximately 119 mm, or in a range between 115 mm to 122 mm, or in a range of 105 mm to 132 mm and a head breadth of approximately 117 mm, or in a range between 113 mm to 119 mm, or in a range between 103 mm to 129 mm. Alternatively, the head 102 when configured as a fairway wood or hybrid may have a head length, breadth and MOI ranges lower than those of a driver.

The golf club 100 may include a shaft 104 connected to or otherwise engaged with the ball striking head 102 as shown in FIG. 1. The shaft 104 is adapted to be gripped by a user to swing the golf club 100 to strike the ball. The shaft 104 can be formed as a separate piece connected to the head 102, such as by connecting to the hosel 110, as shown in FIG. 1. Any desired hosel and/or head/shaft interconnection structure may be used without departing from this invention, including conventional hosel or other head/shaft interconnection structures as are known and used in the art, or an adjustable, releasable, and/or interchangeable hosel or other head/shaft interconnection structure such as those shown and described in U.S. Patent Application Publication No. 2009/0062029, filed on Aug. 28, 2007, U.S. Patent Application Publication No. 2013/0184098, filed on Oct. 31, 2012, and U.S. Pat. No. 8,533,060, issued Sep. 10, 2013, all of which are incorporated herein by reference in their entireties and made parts hereof. The head 102 may have an opening or other access 170 for the adjustable hosel 110 connecting structure that extends through the sole 118, as seen in FIGS. 2 and 9. In other illustrative embodiments, at least a portion of the shaft 104 may be an integral piece with the head 102, and/or the head 102 may not contain a hosel 110, may contain an internal hosel structure, or may not extend through the sole 118. Still further embodiments are contemplated without departing from the scope of the invention.

The shaft 104 may be constructed from one or more of a variety of materials, including metals, ceramics, polymers, composites, or wood. In some illustrative embodiments, the shaft 104, or at least portions thereof, may be constructed of a metal, such as stainless steel or titanium, or a composite, such as a carbon/graphite fiber-polymer composite. However, it is contemplated that the shaft 104 may be constructed of different materials without departing from the scope of the invention, including conventional materials that are known and used in the art. A grip element 106 may be positioned on the shaft 104 to provide a golfer with a slip resistant surface with which to grasp the golf club shaft 104, as seen in FIG. 1. The grip element 106 may be attached to the shaft 104 in any desired manner, including in conventional manners known and used in the art (e.g., via adhesives or cements, threads or other mechanical connectors, swedging/swaging, etc.).

The golf club head 102 shown in the embodiments shown in FIGS. 1-12 include an elongated channel 140 positioned within the sole 118 of the head 102, and which may extend continuously across at least a portion of the sole 118. In other embodiments, the head 102 may have a channel 140 positioned differently, such as on the crown 116, the heel 120, and/or the toe 122. It is also understood that the head 102 may have more than one channel 140, or may have an annular channel extending around the entire or substantially the entire head 102.

As illustrated in FIGS. 2 and 9, the channel 140 of this example structure is elongated, extending between a first end 142 located proximate the heel 120 of the head 102 and a second end 144 located proximate the toe 122 of the head 102. The channel 140 has a boundary that is defined by a first or front edge 146 and a second or rear edge 148 that extend between the ends 142, 144. In this embodiment, the channel 140 extends across the sole, adjacent to and along the bottom edge 128 of the face member 112, and further extends proximate the heel 120 and toe 122 areas of the head 102. The channel 140 is recessed inwardly with respect to the immediately adjacent surfaces of the head 102 that extend from and/or are in contact with the edges 146, 148 of the channel 140, as shown in FIGS. 2 and 9. It is understood that, with a head 102 having a thin-wall construction (e.g., the embodiments of FIGS. 1-12), the recessed nature of the channel 140 creates corresponding raised portions on the inner surfaces of the body 108.

As illustrated in FIGS. 2 and 8-9, the sole 118 may have a plurality of members such that a first member 136 made of a first material, a second member 138 made of a second material, and a third member 160 made of a third material where the channel 140 and the immediate adjacent surfaces to the channel 140 may be formed within the second member 138 and third member 160. The first material may be the same material as the remainder of the club head body 108, while the second material may have a lower modulus of elasticity than the first material and the third material may have a lower modulus of elasticity than the second material. The lower modulus materials may be integrally joined together with the first material prior to forming the sole 118 by welding or a similar integral joining technique or the second member 138 and third member 160 may be integrally joined and subsequently formed as a separate piece of the second and third members and then integrally joined to the club head body 108. The club head body 108 may be constructed as substantially one component such as a casting process or the body may be made as a separate face, crown, sole and hosel component and subsequently joining via a welding or similar process.

FIG. 9 shows a bottom view of the embodiment of FIGS. 1-9. The second member 138 may have a forward edge 137 located towards the front 124 of the club head and a rear edge 139 located towards the rear of the second member. The second member 138 may be rectangular in shape or may have any number of edges even possibly an edge or edges with curvature. The corners of the second member 138 may have generous radii to avoid having sharp corners in a high stress area. Further, the second member 138 of sole 118 may be centered in the heel-toe direction on the sole surface. Alternatively, the second member 138 may be centered at the CFX location as the sole centerline may not be the same as the face centerline. As an additional embodiment, the second member 138 may not be centered at the CFX location or along the centerline of the sole.

The forward most edge 137 of the second member 138 may have a forward most edge that is generally parallel to the ball striking surface 114. The ball striking surface 114 may have a bulge radius measuring from heel-to-toe and a roll radius measuring from crown to sole. This bulge and roll radii may measure between 200 mm to 460 mm. Alternatively, the forward most edge 137 of may not have any curvature. The rear most edge 139 of the second member 138 is generally parallel to the forward most edge 137. The forward edge's 137 location may be defined by a dimension 153 measured from a sole-face intersection point 68 in the Y-Axis 16 direction to the forward most point of forward edge 137 at approximately 15 mm, or within the range of 5 to 20 mm, or within the range of 3 mm to 25 mm. The second member 138 has a center width 156 when measured in the Y-Axis direction between the forward most edge 137 and the rearward most edge 140 within a cross-section created by a plane passing through the face center 40 (for example FIG. 8A). The center width 156 may be approximately 20 mm, or in a range between 10 mm to 28 mm, or in a range between 6 mm to 30 mm. Additionally, the maximum width 155 of the second member 138 measures the span across in the Y-Axis direction from the most forward point of edge 137 of the second member 138 to the most rearward edge 139 of the second member 138. The maximum width 155 of the second member 138 may be approximately 25 mm, in a range between 12 mm and 30 mm, or in a range between 8 mm and 35 mm.

As illustrated in FIG. 9, the second member 138 may have a length 158 that is at least 50% of the club head length 58, or at least 75% of the club head length, or the entire length of the sole 118. The second member length dimension 158 may be defined as the maximum length of the second member 138 measured in the heel-to-toe direction along the X-Axis 14. The second member 138 may be in communication with the interconnecting structure 172, or the interconnecting structure 172 may be entirely within the second member 138. Alternatively, the second member 138 may not be in communication with the interconnecting structure 172.

The thickness of the second and third members 138, 160 may be equal to or less than the surrounding thickness of the first member 136. The overall thickness of the second and third members 138, 160 may be constant or may have a variable thickness. The thickness may be approximately 1.0 mm, within a range of 0.6 mm and 2 mm, or within a range of 0.4 mm to 2.5 mm.

As illustrated in FIGS. 8A and 9, the channel 140 has a width W and a depth D that may vary in different portions of the channel 140. The width W and depth D of the channel 140 may be measured with respect to different reference points. For example, the width W of the channel 140 may be measured between radius end points (see points E in FIG. 8A), which represent the end points of the radii or fillets of the front edge 146 and the rear edge 148 of the channel 140, or in other words, the points where the recession of the channel 140 from the body 108 begins. This measurement can be made by using a straight virtual line segment that is tangent to the end points of the radii or fillets as the channel 140 begins to be recessed into the body 108. This may be considered to be a comparison between the geometry of the body 108 with the channel 140 and the geometry of an otherwise identical body that does not have the channel 140. The depth D of the channel 140 may also be measured normal to an imaginary line extending between the radius end points.

As further illustrated in FIGS. 8 and 8A, a rearward spacing S of the channel 140 from the sole-face intersection point 68 along the Y-axis direction to a most forward point defined using the radius end point of the front edge 146 of the channel 140. If the reference points for measurement of the width W and/or depth D of the channel 140 are not explicitly described herein with respect to a particular example or embodiment, the radius end points may be considered the reference points for both width W and/or depth D measurement. Properties such as width W, depth D, and rearward spacing S, etc., are consistent in all embodiments.

The head 102 in the embodiment illustrated in FIGS. 1-9 has a channel 140 that generally has a substantially constant width W (front to rear) from adjacent surfaces of the sole 118. The channel 140 has a center portion 130 and heel and toe portions 131, 132. In this configuration, the front edge 146 and the rear edge 148 are both generally parallel to the bottom edge of the face member 112 and/or generally parallel to each other along the entire length. In this configuration, the front and rear edges 146, 148 may generally follow the curvature of the bulge radius of the face member 112. In other embodiments, the front edge 146 and/or the rear edge 146 may be angled, curved, etc. with respect to each other and/or with respect to the adjacent edges of the face member 112. The depths D of the heel and toe portions 131, 132 of the channel 140 may decrease from the center portion 130 toward the heel 120 and toe 122, respectively. Alternatively, the depths D of the heel and toe portions 131, 132 may be greater than the center portion 130. Further, in the embodiment shown in FIGS. 2 and 8, the front edge 146 and rear edge 148 at the heel and toe portions 131, 132 are generally parallel to the adjacent edge 128 of the face member 112. In one embodiment, the access 170 for the adjustable hosel 110 connecting structure 172 may be or may not be in communication with and/or may intersect the heel portion 131 of the channel 140. The heel portion 131 around the access 170 may wider than the channel center and toe portions 130, 132 and the portion of the heel channel 131 transitioning to the access 170. The access 170 in this embodiment includes an opening 171 within the channel 140 that receives a part of the hosel interconnection structure 172. In other embodiments, the channel 140 may be oriented and/or positioned differently. For example, the channel 140 may be oriented where at least a portion of the channel 140 may be parallel or generally parallel to one or more of the edges 128 of the face member 112. The size and shape of the elongated channel 140 also may vary widely without departing from this invention.

The channel 140 is substantially symmetrically positioned on the head 102 in the embodiment illustrated in FIGS. 1-9, such that the center portion 130 is generally symmetrical with respect to a vertical plane passing through the geometric centerline of the sole 118 and/or the body 108, and the midpoint of the center portion 130 may also be coincident with such a plane. However, in another embodiment, the center portion 130 may additionally or alternately be symmetrical with respect to a vertical plane (generally normal to the face member 112) passing through the geometric center of the face member CFX 42 (which may or may not be aligned the geometric center of the sole 118 and/or the body 108), and the midpoint of the center portion 130 may also be coincident with such a plane. This arrangement and alignment may be different in other embodiments, depending at least in part on the degree of geometry and symmetry of the body 108 and the face member 112. For example, in another embodiment, the center portion 130 may be asymmetrical with respect to one or more of the planes discussed above, and the midpoint may not coincide with such plane(s). This configuration can be used to vary the effects achieved for impacts on desired portions of the face member 112 and/or to compensate for the effects of surrounding structural features and the impact properties of the face member 112.

The channel 140 in this embodiment has a curved and generally semi-circular cross-sectional shape or profile, with a trough 150 and a sloping, depending front side wall 151 and a sloping depending rear side wall 152 that are smoothly curvilinear, extending from the trough 150 to the respective edges 146, 148 of the channel 140. The trough 150 forms the deepest (i.e. most inwardly-recessed) portion of the channel 140 in this embodiment. The third member 160 forms the trough 150 and a portion of front side wall 151 and rear side wall 152, while the second member 138 forms a portion of the side walls 151, 152 and a portion of the adjacent surfaces to the channel. The first, second, and third members are integrally joined together creating a generally smooth transition between the members. It is understood that the channel 140 may have a different cross-sectional shape or profile, such as having a sharper and/or more polygonal (e.g. rectangular) shape in another embodiment where the front side wall 151 may have a different length or sloping angle than the rear side wall 152. Additionally, the center portion 130 of the channel 140 may have a generally constant depth across the entire length, i.e., between the ends 131, 132 of the center portion 130. In another embodiment, the center portion 130 of the channel 140 may generally increase in depth D so that the trough 150 has a greater depth at and around the midpoint of the center portion 130 and is shallower more proximate the ends 131, 132.

The depth D of the center portion 130 of the channel 140 may be approximately 4 mm, or may be in the range of 2 to 6 mm in another embodiment. Additionally, in one embodiment of a club head 102 as shown in FIGS. 1-9, the width W of the center portion 130 of the channel 140 may be approximately 9 mm, or may be in the range of 6 to 12 mm in another embodiment, or may be in a range of 4 mm to 16 mm. It is understood that the channel 140 may have a different configuration in another embodiment.

The heel and toe portions 131, 132 of the channel 140 may have different cross-sectional shapes and/or profiles than the center portion 130. For example, the heel and toe portions 131, 132 may have a more angular and less smoothly-curved cross-sectional shape as compared to the center portion 130, which has a semi-circular or other curvilinear cross-section. In other embodiments, the center portion 130 may also be angularly shaped, such as by having a rectangular or trapezoidal cross section, and/or the heel and toe portions 131, 132 may have a more smoothly-curved and/or semi-circular cross-sectional shape. The cross-sections may transition smoothly between the center portion 130 and the heel and toe portions 131, 132. Alternatively, the transition between the center portion 130 and the heel and toe portions 131, 132 may be more abrupt and have a step feature where the cross-sectional shape changes.

Further, in one embodiment, the wall thickness T of the channel 140 may be reduced, as compared to the thickness at other locations of the second member 138, to provide for increased flexibility at the channel 140. In one embodiment, the wall thickness(es) T in the channel 140 (or different portions thereof) may be from 0.3-2.0 mm, or from 0.6-1.8 mm in another embodiment. The wall thickness T may also vary at different locations within the channel 140. For example, in one embodiment, the wall thickness T is slightly greater at the center portion 130 of the channel 140 than at the heel and toe portions 131, 132. In a different embodiment, the wall thickness may be smaller at the center portion 130, as compared to the heel and toe portions 131, 132. The wall thickness T in either of these embodiments may gradually increase or decrease to create these differences in wall thickness in one embodiment. The wall thickness T in the channel 140 may have one or more “steps” in wall thickness to create these differences in wall thickness in another embodiment, or the channel 140 may have a combination of gradual and step changes in wall thickness. In a further embodiment, the entire channel 140, or at least the majority of the channel 140, may have a consistent wall thickness T. It is understood that any of the embodiments in FIGS. 1-12 may have any of these wall thickness T configurations.

As discussed earlier, the second member 138 and the channel 140 are spaced from the bottom edge 128 of the face member 112, with a spacing portion 154 defined between the front edge 146 of the channel 140 and the bottom edge 128. The spacing portion 154 comprises a portion of the second member 138 located immediately adjacent the channel 140 and junctures with the front side wall 151 of the channel 140 along the front edge 146 of the channel 140, as shown in FIGS. 2 and 7-9. In various embodiments, the spacing portion 154 may be oriented with respect to the ball striking surface 114 at an acute (i.e. <90°), obtuse (i.e. >90°), or right angle. Force from an impact on the face member 112 can be transferred to the channel 140 through the spacing portion 154, as described below.

The elongated channel 140 of the head 102 shown in FIGS. 1-9 can influence the impact of a ball (not shown) on the face member 112 of the head 102. In one embodiment, the channel 140 can influence the impact by flexing and/or compressing in response to the impact on the face member 112, which may influence the stiffness/flexibility of the impact response of the face member 112. For example, when the ball impacts the face member 112, the face member 112 flexes inwardly, and some of the impact force is transferred through the spacing portion 154 to the channel 140, causing the channel 140 to flex. This flexing of the channel 140 may assist in achieving greater impact efficiency and greater ball speed at impact by reducing the amount of deformation in the golf ball. The more gradual impact created by the flexing also creates a longer impact time, which can also result in greater energy and velocity transfer to the ball during impact. Further, because the channel 140 extends into the heel 120 and toe 122, the head 102 may create higher ball speeds for impacts that are away from the center or traditional “sweet spot” of the face member 112. Additionally, the flexing of the body may affect the launch angle of the golf ball in both a vertical and horizontal direction. It is understood that one or more channels 140 may be additionally or alternately incorporated into the crown 116 and/or sides 120, 122 of the body 108 in order to produce similar effects. For example, in one embodiment, the head 102 may have one or more channels 140 extending completely or substantially completely around the periphery of the body 108, such as shown in U.S. patent application Ser. No. 13/308,036, filed Nov. 30, 2011, which is incorporated by reference herein in its entirety.

As discussed above, the center portion 130 of the channel 140 may have cross-sectional profiles and thicknesses than the heel and toe portions 131, 132. These different cross-sectional profiles and thicknesses combined with the lower modulus of elasticity materials of the second and third members 138, 160 work in conjunction with the properties of the face member 112 to improve the impact efficiency of the club head 102. For instance, the face height 56 and face thickness can play a substantial role with regard to the impact efficiency of the club head. By being cognizant the face properties like the face height 56 and face thickness, one skilled in the art may select the parameters of the second member 138 and channel 140 such as the material selection, the thickness, the cross-sectional profile of the channel, and the position relative to the face to better optimize the club head 102 for improved impact efficiency both on center impacts and impacts away from the center of the face. The portions of the face member 112 around the center 40 are generally the most flexible, and thus, less flexibility from the channel 140 is needed for impacts proximate the face center 40. The portions of the face member 112 more proximate the heel 120 and toe 122 are generally less flexible, and thus, the heel and/or toe portions 131, 132 of the channel 140 are more flexible to compensate for the reduced flexibility of the face member 112 for impacts near the heel 120 and the toe 122. In another embodiment, the center portion 130 of the channel 140 may be more flexible than the heel and toe portions 131, 132, to achieve different effects. It is understood that other structural features on the head 102 other than the channel 140 may influence the flexibility of the channel 140, such as the thickness of the first member 136 positioned either forward or aft of the second member 138 on the sole 118.

The relative dimensions of the second member 138, the third member 160, the channel 140, the face member 112, the first member 136 and other areas of the body 108 may influence the overall response of the head 102 upon impacts on the face member 112, including ball speed, twisting of the club head 102 on off-center hits, spin imparted to the ball, etc. For example, a wider width W channel 140, a deeper depth D channel 140, a smaller wall thickness T at the channel 140, a smaller space S between the channel 140 and the face member 112, and/or a greater face height 56 of the face member 112 can create a more flexible impact response on the face member 112. Conversely, a narrower width W channel 140, a shallower depth D channel 140, a greater wall thickness T at the channel 140, a larger space S between the channel 140 and the face member 112, and/or a smaller face height 56 of the face member 112 can create a more rigid impact response on the face member 112. The length of the channel 140 and/or the center portion 130 thereof can also influence the impact properties of the face member 112 on off-center hits, and the dimensions of these other structures relative to the length of the channel may indicate that the club head has a more rigid or flexible impact response at the heel and toe areas of the face member 112. Thus, the relative dimensions of these structures can be important in providing performance characteristics for impact on the face member 112, and some or all of such relative dimensions may be critical in achieving desired performance. Some of such relative dimensions are described in greater detail below. In one embodiment of a club head 102 as shown in FIGS. 1-12, the length (heel-to-toe) of the center portion 130 is approximately 30.0 mm. It is understood that the properties described below with respect to the center portion 130 of the channel 140 (e.g., length, width W, depth D, wall thickness T) correspond to the dimension that is measured on a vertical plane extending through the face center FC, and that the center portion 130 of the channel 140 may extend farther toward the heel 120 and the toe 122 with these same or similar dimensions, as described above. It is also understood that other structures and characteristics may also affect the impact properties of the face member 112, including the thickness of the face member 112, the materials from which the face member 112, channel 140, or other portions of the head 102 are made, the stiffness or flexibility of the portions of the body 108 behind the channel 140.

The golf club head 102 may be formed using a method with the steps of (a) forming a golf club head body of a first material comprising a heel, a toe, a portion of a crown, and a portion of a sole; (b) forming a face member of a second material comprising a ball striking surface or a face member of a second material comprising a ball striking surface and a portion of the crown; (c) forming a first sole member of a third material comprising a portion of the sole; (d) forming a second sole member of a fourth material comprising a portion of the sole; (e) wherein the first sole member and second sole member are integrally joined to form an elongated channel extending across a portion of the sole in a heel-to-toe direction; and (f) wherein the golf club head body, the face member, and the first sole member and the second sole member are integrally joined together. Further, the fourth material has a modulus of elasticity lower than a modulus of elasticity of the first material, second and third material. The first material may be made of a titanium alloy, such as Ti-6V-4Al, while the third and fourth materials may be formed of material such as a beta-titanium alloy, Gum Metal™, vitreous alloys, metallic glasses or other amorphous metallic materials, non-metallic material, composite materials (carbon fiber and others), or other suitable material.

Face Design

The ball striking face may work in conjunction with the channel to improve the impact efficiency. The face member 112 may be formed of a single material or formed of a plurality of materials connected by an integral joining technique. For example, if the face member 112 may be integrally formed where a first material and a second material are welded as a flat sheet and subsequently formed either cold forming, forging, or other similar process to the appropriate shape to be joined to the club head body 108.

Additionally, the ball striking face portion 114 of the face member 112 may have constant thickness or it may have variable thickness. In one embodiment, the face member 112 of the head 102 in FIGS. 1-9 may be made from titanium alloy (e.g., Ti-6Al-4V alloy or Ti-15V-3Cr-3Sn-3Al, or other alloy); however, the face member 112 may be made from other materials in other embodiments such as a steel, carbon composite or even carbon fiber reinforced polymer.

It is understood that the face member 112, the body 108, and/or the hosel 110 can be formed as a single piece or as separate pieces that are joined together. The body 108 being partially or wholly formed by one or more separate pieces connected to the face member. These pieces may be connected by an integral joining technique, such as welding, cementing, or adhesively joining. Other known techniques for joining these parts can be used as well, including many mechanical joining techniques, including releasable mechanical engagement techniques. As one example, a body member formed of a single, integral, cast piece may be connected to a face member to define the entire club head. The head 102 in FIGS. 1-9 may be constructed using this technique, in one embodiment. As another example, a single, integral body member may be cast with an opening in the face and the sole. The body member is then connected to a face member, and a separate sole piece is connected within the sole opening to completely define the club head. Such a sole piece may be made from a different material, beta-titanium, Gum Metal™, polymer or composite. As a further example, either of the above techniques may be used, with the body member having an opening on the top side thereof. A separate crown piece may be used to cover the top opening and form part or the entire crown 116, and this crown piece may be made from a different material, beta-titanium, Gum Metal™, polymer or composite.

Additional Embodiments of Channel Feature

The previously discussed features apply to the alternative embodiments discussed below and with the exception of the distinguishing features discussed.

FIG. 10 shows an alternate embodiment of head 202 similar in length and thickness to the embodiment shown in FIGS. 1-9. For embodiment of FIG. 10, the features are referred to using similar reference numerals under the “2xx” series of reference numerals, rather than “1xx” as used in the embodiment of FIGS. 1-9. Accordingly, certain features of the head 202 that were already described above with respect to head 102 of FIGS. 1-9 may be described in lesser detail, or may not be described at all. The sole 218 including the channel 240 may be made of a plurality of members. The first member 236 comprises the majority of the sole where the second member 238 and third member 260 may comprise the channel and the adjacent surfaces to the channel. The second member 238 may comprise a portion of the forward surface 251, a portion of the rear surface 252. Additionally, the second member may also comprise a portion of the adjacent surfaces to the channel 240. The third member 260 comprises a connecting member forming the trough 250 between the side walls 251, 252 spanning an opening 265 formed in the sole positioned on an interior surface of the side walls and overlaps a portion of the side walls. Alternatively, the third member 260 may be positioned on an exterior surface of the side walls. The first, second, and third members may be made of a first, second, and third material respectively. The second and third members 238, 260 may be any material having a lower modulus of elasticity than the first material comprising the remainder of the sole 218. For example the second and third members 238, 260 may be a material with a lower modulus of elasticity than the first material such as a beta titanium alloy, Gum Metal™, vitreous alloys, metallic glasses or other amorphous metallic materials, composite materials (carbon fiber and others), or other suitable material, where the adjacent material may be a T-6V-4Al or Ti-8Al-1Mo-1V alloy. The first and second members may be joined preferably by a welding process, but may be joined by any integral joining technique. The second and third members may be joined together with a bonding, brazing, or adhesion process using a lap joint where the second member 238 may span an opening 265 in sole 218 the club head body 208. The lap joint may have an overlap dimension L that may be approximately 4 mm in width or may be in a range between 2 mm and 6 mm. The channel 240, the second member 238, and the third member 260 may be formed having a similar shape, length, width, thickness, and location similar to the previous embodiments shown in FIGS. 1-9.

The lap joint may create a localized stiffer region caused by the overlapped material region, which may transmit energy from the impact of a golf ball that may increase the deformation of the more flexible region of the third member 260 and the trough 250 formed within the third member 260. Similar to previous embodiments, the channel 240 may have a symmetrical or asymmetrical cross-sectional profile.

For embodiment of FIG. 11, the features are referred to using similar reference numerals under the “3xx” series of reference numerals, rather than “1xx” as used in the embodiment of FIGS. 1-9. Accordingly, certain features of the head 302 that were already described above with respect to head 102 of FIGS. 1-9 may be described in lesser detail, or may not be described at all. Unless specifically mentioned, the channel 340 and the sole members are dimensionally measured the same as channel 140 and the sole members of in the embodiment described in FIGS. 1-9. In this embodiment, the sole 318 may be made of a plurality of members where the first member 336 made of a first material comprises the majority of the sole 318 and a second member made of a second material may comprise a portion of side walls 351, 352 and a portion of trough 350 of a heel side 320 and of a toe side 322 or alternatively, the second member may be located only on a toe side 322 or only on a heel side 320. The third member 360 made of a third material may comprise a portion of the side walls 351, 352, and trough 350 of the center portion 330 of the channel 340. The second and third members 338, 360 may be any material having a lower modulus of elasticity than the first material of the first member 336 comprising the remainder of the sole 318. Alternatively, the third material may have a lower modulus of elasticity than the first material and the second material. For example, the second and third members 338, 360 may be materials with lower moduli of elasticity than the first material such as a beta titanium alloy, Gum Metal™, vitreous alloys, metallic glasses or other amorphous metallic materials, composite materials (carbon fiber and others), or other suitable material, where the first material may be a Ti-6V-4Al or Ti-8Al-1Mo-1V alloy. The first, second, and third members may be joined by any integral joining technique.

The third member 360 may have a generally rectangular shape when viewed perpendicular to the sole and may comprise a surface area larger than a surface area of the second member 338. Alternatively, the third member 360 may comprise a smaller surface area than a surface area of the second member 338. Additionally, the second member 338 and third member 360 may integrally joined together prior to connecting to the club head body 308.

FIG. 12 shows another alternate embodiment of head 402 similar in length and thickness to the embodiment shown in FIGS. 1-9. For embodiment of FIG. 12, the features are referred to using similar reference numerals under the “4xx” series of reference numerals, rather than “1xx” as used in the embodiment of FIGS. 1-9. Accordingly, certain features of the head 402 that were already described above with respect to head 102 of FIGS. 1-9 may be described in lesser detail, or may not be described at all. Unless specifically mentioned, the channel 440 and the sole members are dimensionally measured the same as channel 140 and the sole members of in the embodiment described in FIGS. 1-9. In this embodiment, the sole 418 may be made of a plurality of members where the first member 436 made of a first material comprises the majority of the sole 418 and a second member 438 made of a second material may comprise a portion of the forward surface 451 and a portion of the rear surface 452. The third member 460 comprises a connecting member between the side walls 451, 452 spanning an opening 465 formed in the sole where the third member 460 may be substantially U-shaped where such that the third member may have a semi-circular shape with an inflection point 470 positioned proximate the sole 418 of the golf club head 402. The U-shaped profile may be positioned on an angle 461 from parallel to the X-axis 14 and perpendicular to the ground plane 6. Angle 461 may be equivalent to the loft angle 48 or may be in a range of 0 degrees to 30 degrees. The second and third members 438, 460 may be a material having a lower modulus of elasticity than the material of the first member 436 comprising the remainder of the sole 418. Alternatively, the third material may have a lower modulus of elasticity than the first material and the second material. For example, the second and third members 438, 460 may be materials with lower moduli of elasticity than the first material such as a beta titanium alloy, Gum Metal™, vitreous alloys, metallic glasses or other amorphous metallic materials, composite materials (carbon fiber and others), or other suitable material, where the first material may be a Ti-6V-4Al or Ti-8Al-1Mo-1V alloy. The first, second, and third members may be joined by any integral joining technique.

The various dimensions of the center portion 130 of the channel 140 of the club head 102 in FIGS. 1-9 may have relative dimensions with respect to each other that may be expressed by ratios. In one embodiment, the channel 140 has a face height 56 and a depth D in the center portion 130 that are in a ratio of approximately 9:1 to 27:1 (face height/depth) for a driver configuration, while as a fairway wood configuration or hybrid club may have a ratio of face height to depth of 6:1 to 20:1. Additionally, in one embodiment, the channel 140 has a width W and a depth D in the center portion 130 that are in a ratio of approximately 1:2 to 4:1 (width/depth) in a driver configuration, while as a fairway wood configuration or hybrid club may have a ratio of a width W and a depth of 1.3:1 to 2:1.

For all of the embodiments, the center width 156 of the second sole member 138 when measured from the front to the back of head 102 may be expressed as a ratio of the breadth dimension 60 of head 102. For example, the ratio of the center width dimension (expressed as dimension 156 in FIG. 8A) to the overall breadth of the golf club head 60 may be approximately 1:5 for a driver or within a range between 1:3.5 and 1:13. Likewise, for a smaller golf club head like a fairway wood, this ratio of center width 156 to overall breadth of the golf club head may be approximately 1:3 or within a range between 1:2.5 and 1:9. For an even smaller golf club head like a hybrid, this ratio of center width 156 to overall breadth 60 of the golf club head may be approximately 1:2.5 or within a range between 1:2 and 1:7.

Likewise, the size of the sole member 138 when measured from the front to the back of the head 102 may be expressed as a ratio of the face height dimension 56 of the head 102. For example, the ratio of the center width dimension (expressed as dimension 156 in FIG. 8A) the ratio of the center width 156 to the face height dimension 56 may be approximately 1:3 for a driver or within a range between 1:2 and 1:6. Likewise, for a smaller golf club head like a fairway wood or a hybrid, this ratio of center width 156 to face height of the golf club head may be approximately 1:1.8 or within a range between 1:1 and 1:4.

Additionally, the relationship between the modulus of elasticity of the material of the third member 160 to the modulus of elasticity of the material of the club head body 108 may be where the modulus of elasticity of the material of the third member may be at least 5% lower than the modulus of the club head body 108, or at least 10% lower, or even at least 20% lower. The relationship between the modulus of elasticity of the material of the third member 160 to the modulus of elasticity of the material of the second member 138 may be where the modulus of elasticity of the material of the third member may be at least 5% lower than the modulus of the second member 138, or at least 10% lower. Lastly, the relationship between the modulus of elasticity of the material of the second member 138 to the modulus of elasticity of the material of the club head body 108 may be where the modulus of elasticity of the material of the third member may be at least 5% lower than the modulus of the club head body 108, or at least 10% lower. The modulus of the material is recognized to be in the proper heat treatment condition of the finished golf club head to enable the golf club head to be durable as one skilled in the art would define it.

It is understood that one or more different features of any of the embodiments described herein can be combined with one or more different features of a different embodiment described herein, in any desired combination. It is also understood that further benefits may be recognized as a result of such combinations. Golf club heads 102 may contain any number of sole features such as channels or lower modulus regions in combination with the features of the embodiments disclosed herein.

Golf club heads 102 incorporating the body structures disclosed herein may be used as a ball striking device or a part thereof. For example, a golf club 100 as shown in FIG. 1 may be manufactured by attaching a shaft or handle 104 to a head that is provided, such as the heads 102, et seq., as described above. “Providing” the head, as used herein, refers broadly to making an article available or accessible for future actions to be performed on the article, and does not connote that the party providing the article has manufactured, produced, or supplied the article or that the party providing the article has ownership or control of the article. Additionally, a set of golf clubs including one or more clubs 100 having heads 102 as described above may be provided. For example, a set of golf clubs may include one or more drivers, one or more fairway wood clubs, and/or one or more hybrid clubs having features as described herein. In other embodiments, different types of ball striking devices can be manufactured according to the principles described herein. Additionally, the head 102, golf club 100, or other ball striking device may be fitted or customized for a person, such as by attaching a shaft 104 thereto having a particular length, flexibility, etc., or by adjusting or interchanging an already attached shaft 104 as described above.

The ball striking devices and heads therefore having the channel 140 made of a lower modulus material than the remaining body as described herein provide many benefits and advantages over existing products. For example, the flexing of the members 138, 160 combined with the flexing of the channel 140 may result in a smaller degree of deformation of the ball, which in turn can result in greater impact efficiency and greater ball speed at impact. As another example, because the second member 138 combined with the channel 140 may create more flexible heel and toe regions, which can enable the head 102 to achieve increased ball speed on impacts that are away from the center or traditional “sweet spot” of the ball striking surface 114. The greater flexibility at those areas helps to offset the reduced flexibility due to decreased face height at those areas, further improving ball speed at impacts that are away from the center of the ball striking surface 114. Further benefits and advantages are recognized by those skilled in the art.

The benefits of the channel 140 with lower modulus materials described herein can be combined together to achieve additional performance enhancement. Further benefits and advantages are recognized by those skilled in the art.

While the invention has been described with respect to specific examples including presently preferred modes of carrying out the invention, those skilled in the art will appreciate that there are numerous variations and permutations of the above described systems and methods. Thus, the spirit and scope of the invention should be construed broadly as set forth in the appended claims. 

What is claimed is:
 1. A golf club head comprising: a club head body member made of a first material comprising a heel, a toe, a portion of a crown, a portion of a sole; a face member made of a second material comprising a central portion of the striking face and a portion of the crown adjacent to the striking face; and an elongated channel extending across a portion of the sole in a heel-to-toe direction, wherein the elongated channel is recessed from adjacent surfaces of the sole and has a plurality of side walls and a depth of recession from the adjacent surfaces of the sole, wherein the sole comprises a plurality of materials with the elongated channel and the adjacent surfaces comprising a third material and a fourth material and the remainder of the sole comprising the first material, wherein the adjacent surfaces of the elongated channel and a portion of the side walls of the elongated channel are made of the third material and the remainder of the elongated channel is made of the fourth material.
 2. A golf club head of claim 1, wherein the third material has a modulus of elasticity that is lower than a modulus of elasticity of the first material.
 3. A golf club head of claim 2, wherein the fourth material has a modulus of elasticity that is lower than a modulus of elasticity of the third material.
 4. A golf club head of claim 1, wherein the elongated channel has a front edge, a rear edge, and a width defined between the front and rear edges, wherein the width of the elongated channel is substantially constant.
 5. A golf club head of claim 1, wherein the third material is a beta-titanium alloy.
 6. A golf club head of claim 1, wherein the second material has a modulus of elasticity that is lower than a modulus of elasticity of the first material.
 7. A golf club head of claim 1, wherein the fourth material is gum metal.
 8. A golf club head comprising: a club head body member made of a first material comprising a heel, a toe, a portion of a crown, a portion of a sole; a face member made of a second material comprising a central portion of the striking face; and an elongated channel extending across a portion of the sole in a heel-to-toe direction, wherein the elongated channel is recessed from adjacent surfaces of the sole and has a plurality of side walls and a depth of recession from the adjacent surfaces of the sole, wherein the sole comprises a plurality of materials with the elongated channel and the adjacent surfaces comprising a third material and a fourth material and the remainder of the sole comprising the first material, wherein the adjacent surfaces of the elongated channel and a portion of the side walls of the elongated channel are made of the third material and the remainder of the elongated channel is made of the fourth material.
 9. A golf club head of claim 8, wherein the third material has a modulus of elasticity that is lower than a modulus of elasticity of the first material.
 10. A golf club head of claim 8, wherein the fourth material has a modulus of elasticity that is lower than a modulus of elasticity of the third material.
 11. A golf club head of claim 8, wherein the elongated channel has a front edge, a rear edge, and a width defined between the front and rear edges, wherein the width of the elongated channel is substantially constant.
 12. A golf club head of claim 8, wherein the third material is a beta-titanium alloy.
 13. A golf club head of claim 8, wherein the fourth material is gum metal.
 14. A golf club head comprising: a club head body member made of a first material comprising a heel, a toe, a portion of a crown, and a portion of a sole; a face member made of a second material comprising a central portion of the striking face; and an elongated channel extending across a portion of the sole in a heel-to-toe direction, wherein the elongated channel is recessed from adjacent surfaces of the sole and has a plurality of side walls and a depth of recession from the adjacent surfaces of the sole, wherein the sole comprises a plurality of materials where the elongated channel and the adjacent surfaces comprises a second material and a third material and the remainder of the sole comprising the first material, wherein the adjacent surfaces of the elongated channel and a portion of the side walls of the elongated channel are made of the third material and a connecting member attached to the side walls is made of the fourth material, wherein the fourth material has a modulus of elasticity lower than the third material and the third material has a modulus of elasticity lower than the first material.
 15. A golf club head of claim 14, wherein the third material is gum metal.
 16. A golf club head of claim 14, wherein the third material is non-metallic.
 17. A golf club head of claim 14, wherein the connecting member has an asymmetrical cross-sectional profile.
 18. A golf club head of claim 14, wherein the connecting member covers an opening to an interior cavity of the golf club head body.
 19. A golf club head of claim 14, wherein the elongated channel has a front edge, a rear edge, and a width defined between the front and rear edges, wherein the width of the elongated channel is substantially constant.
 20. A golf club head of claim 14, wherein the connecting member has a cross-sectional shape that is substantially U-shaped.
 21. A method of forming a golf club head, comprising: forming a golf club head body of a first material comprising a heel, a toe, a portion of a crown, and a portion of a sole; forming a face member of a second material comprising a ball striking surface; forming a first sole member of a third material comprising a portion of the sole; and forming a second sole member of a fourth material comprising a portion of the sole, wherein the golf club head body, the face member, and the first sole member and the second sole member are integrally joined together, wherein the first sole member and second sole member are joined to form an elongated channel extending across a portion of the sole in a heel-to-toe direction.
 22. A method of claim 21, wherein the fourth material has a modulus of elasticity lower than a modulus of elasticity of the first material.
 23. A method of claim 21, wherein the fourth material has a modulus of elasticity lower than a modulus of elasticity of the third material.
 24. A method of claim 21, wherein the first material is a titanium alloy.
 25. A method of claim 21, wherein the third material is a beta-titanium alloy.
 26. A method of claim 21, wherein the third material is gum metal.
 27. A method of claim 21, wherein the face member comprises a portion of the ball striking surface and a portion of the crown.
 28. A method of claim 21, wherein the golf club head body, the face member, and the sole member are welded together.
 29. A method of claim 21, wherein the golf club head body and the sole member are brazed together.
 30. A method of claim 21, wherein the golf club head body and the sole member are adhesively joined together.
 31. A golf club head comprising: a club head body member made of a first material comprising a heel, a toe, a portion of a crown, and a portion of a sole; a face member made of a second material comprising a portion of the striking face and a portion of the crown adjacent to the striking face; and an elongated channel extending across a portion of the sole in a heel-to-toe direction, wherein the elongated channel is recessed from adjacent surfaces of the sole and has a plurality of side walls and a depth of recession from the adjacent surfaces of the sole, wherein the sole comprises a plurality of materials with the elongated channel and the adjacent surfaces comprising a third material and a fourth material and the remainder of the sole comprising the first material, wherein the adjacent surfaces of the elongated channel and a portion of the side walls of the elongated channel are made of the third material and the remainder of the elongated channel is made of the fourth material, wherein the third material has a modulus of elasticity that is lower than a modulus of elasticity of the first material, wherein the fourth material has a modulus of elasticity that is lower than a modulus of elasticity of the third material, wherein the third material has a ratio of center width compared to club head breadth when measured in the Y-Axis direction of ratio between 1:3.5 and 1:13. 